Mossbauer studies of thermal power plant coal and fly ash

Iron-57 Mossbauer spectroscopic studies were carried out at room temperature on samples of coal, slag ( bottom ash) and mechanical ash collected from Bhatinda ( India) thermal power plant. Hyperfine parameters such as isomer shift, quadrupole splitting and total internal magnetic field of Fe-57 nuclei were used to characterize various iron-bearing minerals. The observed parameters indicate the presence of pyrite, siderite and ankerite in coal sample while magnetic fractions of mechanical ash and slag samples show the formation of hematite and Al-substituted magnesio-ferrite. The non-magnetic fraction of slag ash shows the dominance of Fe2+ phases while that of mechanical ash demonstrates the formation of both Fe2+ and Fe3+ phases. These findings are compared with Mossbauer and magnetic susceptibility studies on fly ash samples of Panipat ( India) thermal power plant reported earlier.